The present invention relates to the distribution of timing information between two or more devices, and more particularly, the timing information being quantum authenticated.
The Global Positioning System (GPS) provides accurate timing signals from a constellation of satellites. GPS timing signals can be used either for clock synchronization or, when multiple signals are received, for geolocation. GPS signals are encrypted for military applications, but public GPS signals are not encrypted. Moreover, public GPS signals are formatted according to a well-known and easily reproducible scheme. Consequently, public GPS signals are prone to spoofing attacks in which an adversary broadcasts a false GPS signal with the intent of fooling a GPS receiver into reporting an incorrect location and/or time.
Currently, the electrical power grid relies on GPS for the distribution of accurate timing information with better than 1 millisecond resolution. However, utilities have no control over GPS signals, and, as noted above, GPS signals are vulnerable to spoofing or denial of service attacks. Alternatives that do not rely on GPS signals have been proposed, including terrestrial radio beacons (e.g., eLORAN and WWV) and time correlated methods (e.g., encrypted military GPS signals). However, many of these techniques address only the distribution of timing information, and not the security and integrity of that information.
The lack of alternative secure technologies for time reference and distribution can leave the electrical grid vulnerable to black outs and damage to critical infrastructure. Of particular importance are electrical distribution systems that service customers in urban and suburban areas with load densities that can exceed 60 MW and 3 MW per square mile, respectively. Accurate management of electrical load, generation, and delivery is performed using state estimation and by monitoring key parameters of the electrical grid over a wide area. One instrument that provides this valuable information is the phasor measurement unit (PMU), which delivers accurate snapshots of the grid state at high temporal resolution. However, the current generation of PMUs is dependent on GPS for time synchronization. This dependence on GPS technology leaves these valuable electrical grid assets vulnerable to malicious denial-of-service or spoofing attacks that can bring harm to vital equipment and economic interests.
Accordingly, there remains a continued need for an improved system and method for time synchronization in the electrical power grid and other applications.